The present disclosure relates generally to valves for fluid pumping systems. More particularly, the present disclosure relates to adjustable stops for check valves.
Fluid pumping systems are typically used to pressurize materials that are applied using various spray systems. A single spray system can be used to dispense a variety of fluids, such as paints, varnishes, textured coatings, solvents, epoxies, polyurethane and the like. Each of these fluids has a different viscosity, which affects the quality of the sprayed fluid and the efficiency of the pumping system. It is, therefore, desirable to adjust settings of the spray system to accommodate the viscosities of different fluids. One such setting is the opening size at the low pressure inlet of the pump, which is typically determined by an inlet check valve. Thick fluids require large inlet openings to permit a sufficient volume of fluid through the inlet. Inlet openings that are too small for a thick fluid can cause undesirable suction to form in the pump if the fluid cannot enter the inlet fast enough. Thin fluids only require small inlet openings to properly prime the pump and to run efficiently. Too much travel of the ball may cause wear of the ball and ball seat due to excess inertia of the ball, and may reduce pump efficiency. In conventional spray systems, adjustment of the inlet opening requires disassembly of the spray system. For example, U.S. Pat. No. 7,025,087 to Weinberger et al. discloses an inlet ball valve having shims that change the inlet opening size. In order to add or remove shims, however, the pump must be disassembled, which is inconvenient and inefficient. There is, therefore, a need for a more expedient inlet opening adjustment mechanism.